Pneumatic conveyer



Dec. 7 1926;

J. CRITES ET AL 'PNEUMATYIC CONVEYER Filed April 25, 1925 2 Sheets-Sheet l Dec. 7 1926. 1,609,401

J. CRITES ET AL PNEUMATIC CONVEYER Filed April 25, 1925 2 Sheets-Sheet 2 x... I ,I I

Patented JOE CRITES, 0F EVANSTON, AND FRED I. RAYMOND, 0F RIVER FOREST, ILLINOIS, AS- SIGNORS TO THE RAYMOND BROTHERS IMPACT PULVERIZER COMPANY, OF CHI- OAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

PNEUMATIC CONVEYER.

Application filed .April as, 1925. Serial Nb; 25,761.

Our invention relates to pneumatic conveying apparatus for bulk materials of granular or pulverulent character and has for its object to provide certain new and improved arrangements and devices for in-' troducing material in measured quantities into the air current by which the material is conveyed from one place to another and for giving the material an initial forward propulsion by impact which overcomes its inertia, thereby preventing the inflow of the material into the conveying duct from arresting or diminishing the velocity of the air current. While the mechanism for-in-' troducing the granular, or pulverulent material into the conveying duct provided by our invention is of particular utility in this situation such device might be "used in other places where measured quantities of material are to be fed into a space, and particularly a space which is under pressure.

A further object of the invention is to provide certain novel improvements relating to the feed of the material to the conveying conduit adapted particularly to an apparatus employing a rotatable pocket feeder for this purpose.

The invention is illustrated, in certain preterred embodiments, in the accompanying drawings wherein Fig. 1 is a vertical sectional view of an apparatus embodying the invention in one form, and

Fig. 2 is a similar view of a modified form of the invention.

Referring first to Fig. 1 of the drawings, the conveying duct is composed preferably of a substantially horizontal pipe 10 and a substantially vertical pipe 11. The movement of air and suspended solids through the duct is produced by anysuitable apparatus. We have shown a compressor 12 of common type, the eduction pipe 13 of which isconnected with the vertical'leg 11 of the conveyer duct. Preferably, but not necessarily, the pipe 13 is of the same or larger diameter than conveyer pipe 10 so air passes from one pipe to the other without resistance and in relatively large volumes. The intention is to use a relatively low air pressure, for example, ten pounds per square inch although the invention is not to be considered as limited to 'this particular pressure. Arranged at the upper end of the i pipe 11 of the conveyer duct is a'casing 14 into the top of which projects the spout 15 of a feed chute or funnel 16. Arranged in the casing under the spout of the feed chute is a structure 17 in the form of an,inverted channel, the web 18 of which is adapted to receive and support the stream of material entering the casing from the feed chute.

The structure 17, and the valves to be here- 'inafter' mentioned, provide within the casing two 'feed passageways 19, 20. 21 is a valve opening into the passage 19 from the chamber or space 22 below the feed chute, this valve being of the flap valve type, preferably flexible and attached at its upper edge to a flange 23 depending from the top wall 24 of the casing. 25 is a similar valve opening into passage 20 from chamber 22. 26 and 27 are similarvalves secured to the lower edges of the flanges 28, 29 of the channel structure 17. The valves 26 and 27 open into the conveyer duct from the passages 19 and 20, respectively. The casing is formed on each side with an opening and in these openings are set flexible diaphragms 30,31 which are connected by pitmen 32 with a horizontally vibrating yoke 33, the yoke beingo given reciprocating movements by any suitable mechanism (not shown). I

At the junction between the conveyer pipes 10 and 11 is arranged a cylindrical casin 34 in which casing is a rotary impact impeller 35 with blades 36 adapted to act upon material falling through pipe 11 and forward the same in the direction of the air current. The impeller wheel is driven by any suitable means. We have indicated a pulley 37 on the shaft 38 of the impeller wheel, whichpulley is driven by a belt 39. The operation of the mechanism shown in Fig. 1 and above described is as follows: Movement of the air and suspended pan. ticlesthrough the conveyer duct is efl'ected by the rotary pump or compressor 12. The pulverulent or granular material flowsinto the top of'casing 14 throughgthe feed chute 16, the stream of material being supported on surface 18. Yoke 33 is given vibratory movements in a horizontal direction caus- A ing the flexible diaphragms 30, 31 to be moved back and forward. The outward I sure or suction through the feed hopper.

the air current intermittently in charges,,

' the quantities of which are uniform or substantially so. The charges of material de- 15 livered from the hopper into casing 14 fall into dead air spaces, the lower valve being closed in each case. Vhen either lower valve" is opened the corresponding upper valve is closed-so that there is no back pres- When solids are fed into an air current their inertia tends to arrest or-diminish the velocity of the current. The function of the lmpeller wheel is to give a forward movement by impact to the solid particles which.

prevents. thesolid material from checking the *air current. Preferablv the impeller wheel is operated at a speed. corresponding to the velocity conveyer duct. v

In Fig. 2 I have shown an apparatus modi fied in respect to the means employed for feeding the material into the conveying duct or conduit. This form of the invention con- :55 templates the use of a rotary pocket feeder.

4O designates the vertical leg of the conveying duct and 41 the horizontal leg between which is arranged a rotary impeller 42 of substantially the same construction as the impeller shown in Fig. 1 and previously" described. 43 is an air compressor and 4 a pipe leading front the compressor to the upper end of duct 40. The means for feeding the material into duct 40 consists of a hopper 45 and a rotary pocket feeder 46 having an overshot movement, as indicated by the arrow, the feeder being fixed to a shaft.

'47 and being arranged in a cylindrical casing 48' having-an o ening 49 on the side of 50 the hopper and a discharge opening 50 into the duct 40. 51 is a vane in the duct 40 having a curved lip'52 projecting into the discharge opening 50 of the'pocket feeder casing, the vane being arranged so as to di- 55 vert a certain amount of air into the pogkets as they come to emptying position so as to clear them of any adherent material. 53 is a relief pipe tapped into the bottom of the feeder casing and extending to the induction pipe 54: of the compressor. The purpose of this pipe is to relieve the pockets of air q; ressu're which might otherwise tend to im- ,pede the flow of the'matcrialifro'm the hop-- per into the pockets.

-While' we have. described our invention of-the air in this part of the in two preferred embodiments, it is realized v that changes might be made without departure from the principles. of the invention. Therefore we desire to be understood as intending to cover by this patent all. modifications within the scope of the'appended claims.

We claim: v v

1; In a pneumatic conveyer for granular or pulverulent material. the combination of a duct conveying material in a substantially horizontal direction, means for forcing air under pressure into said duct. to create a current of air therethrough,means for feeding the pulverulent material'by gravity into this air current, and an impeller positioned in the duct below the feeding means and acting'on the material suspended in the air current to forward the same in the direction of the air current.

2. In a neumatic conveyer for granular or pulveru ent material, the combination of a duct'for conveying material in a substantially horizontal direction, means for forcing air'under pressure into said duct to create a current of air therethrough, means for feeding the pulverulent material by gravity into this air current, and a rotary impact impeller positioned in the duct below the feeding means and acting on the material suspended in the air current to forward thesame in thetlirection of the air current;- Q In a pneumatic conveyer for granular or pnlverulent, material, the combination of v a conveying duct, having a substantially horizontal leg and a substantially vertical leg, means for forcing air undenpressure into the vertical. leg to create a downward current of air therethrough, means for feeding the pulyerulent material by gravity into this air current, and an impellor located between the. legs of the duct to act upon the material and forward same in the direction of the air current through the horizontal leg.

4. In apneumatic conveyer fo r granular or pu'lverulent material, the combination of a conveying duct, having a substantially horizontal leg and a substantially vertical leg, means for forcingair under pressure into the vertical leg to create a downward current of air therethrough. means for feeding the pulverulent material gravity into this air current, and a rotary impact impellor located within the duct at the junction of ,the legs for acting upon the material to 120 forward .same in the direction of the air current through the horizontal leg. v

5. In a pneumatic conveyer forgranular or pulverulentmaterial, the combination of a conveying duct, means for creating a move- 12 ment of air therethrough, and mechanism for feeding material directly into jsaid air current in said duct comprising a chamber into which the material is initially intro duced, a passageway of variable volume be- 1 tween said chamber and duct, an inlet valve between said chamber and passageway, an

outlet valve between said passageway and duct, and means for alternately increasing and decreasing the volume of the passageway whereby said valves are alternately opened and closed.

6. In a pneumatic conveyer for granular or pulverulent material, the combination of a conveying duct, means for creating a movement of air therethrough, and mechanism for feeding materialinto said duct comprising a chamber into which the material is initiallyintroduced, a passageway between said chamber and duct, a valve between said chamber and passageway, a valve between said passageway and duct, and means for opening each of the valves and closing the other in alternation and for alternately providing a suction and pressure which draws a charge of material into the passageway and thereafter forces the same into the duct.

7. In a pneumatic conveyer for granular or pulverulentmaterial, the combination of a conveying duct, means for creating a movement of air therethrough, and mechanism for feeding material into said duct comprising a chamber into which the material is initially introduced, a passageway between said chamber and. duct, a-valve between said chamber and passageway, a valve be-- tween "said passageway and duct, and means producing alternately suction and pressure in the passageway operating to open each of the valves and close the other valve in al teination.

8. In a pneumatic conveyer for granular or pulverulent material, "the combination of a conveying duct, means for creating a movement of air therethrough, mechanism for feeding material into said. duct comprising a chamber into which the material is initially introduced, a passageway between said chamber and duct, a valve between said chamber and passageway, a valve between said passageway and duct, which valves are adapted to be opened and closed in alternation, a flexible diaphragm forming part ofthe wall of said passageway, and means for vibrating said diaphragm.

9. In a pneumatic conveyer'for granular or pulverulent material, the combination of a conveying duct, means for creating a movement of air therethrough,- mechanism for feeding material into said duct comprising a chamber into which the material is initial- "ly introduced, a passagewaybetween said chamber. and duct, a valve between said chamber and passageway, a valve between said passageway and duct opening oppositely from the passageway and opened and closed by suction and pressure in said passageway, and means for alternately producing suction and pressure in said passageway.

10, In a pneumatic conveyer for granular or pulvcrulent material, the combination of a conveying duct, means for creating amovement of air therethrough, mechanism for feeding material into said duct comprising a chamber into which the material is initially introduced, a passageway between said chamber and duct, a valve between said chamber and passageway, a valve between said passageway and duct opening oppositely from the passageway and opened and closed by suction and pressure in said passageway, and a flexible diaphragm for alternately rarefying and compressing the air in said passageway.

11, In a pneumatic conveyer, the combination of a conveying. duct, means for.

creating a movement of air therethrough,

and mechanism for feeding material into said duct comprising passageways leading from opposite sides of the chamber to the.

duct, a pairof valves between said chamber and. passageways opening into the passageways, a pair of valves between said passageways and duct which open intgf the duct, and means for rarefying the air in each of said passageways alternately and compress ing the air in the other passageway.

12. In a pneumatic conveyer, the combination of a conveying duct, means for creating a movementwf air therethrough, mechanism for feeding material into said duct compris- -1ng passageways leading from opposite s des ofthe chamber to the duct, a pair of valves between sald chamber and passageways opening into the passageways, a pair of valves between said passageways and duct which; open into theduct, a pair of dia phragms associated with said passageways, respectively, and means for moving said diaphragms first in one direction and then in the other.

13. In a pneumatic conveyer, the combination of a conveying duct, means for creating a movement of air therethrough, and mecha nism for feeding the material' i-nto said duct comprising passageways leading from opposite sides of the chamber --to the duct, a pair of valves between said chamber and passageways opening into the passageways by suction and closed by pressure, a pair of valves between said passageways and duct which open into the duct by pressure and are closed by suction, a pair of diaphragms associated with said passageways respectlve ly, and means for moving said diaphragms first in one direction and then in the other.

14. In a pneumatic conveyer, the combination of a conveying duct, means for creating a movement of air therethrough, and mechanism forfeeding material into said duct comprising passageways leading from opposite sides of the chamber to the duct, a pair "of valves between said chamber and passageways opening into the passageways, a pairof Y valves between said passageways and duct which open into the duct, andmeans for alternately reversing the movements of the valves so that when one of the firstnamed pair of valves is opened the valve of the second named pair which is on the other.

side of the apparatus is also opened and the other twovalves closed.

15. Inapneumatic conveyer for granular or pulverulent material, the combination of aconveying duct, means for creating a movement of air therethrough, and mechanism I for feeding material into said duct compriscomprising a casing arranged above said.

ing a chamber into which'the material is initially introduced, a passageway between said chamber and duct, flexible flap valves between said chamber and passageway. and

passageway and duct, and means for alter nat'ely producing suction and pressure in sa1d passageways operating to open said valves in alternation and close the other yalve.

16. In a pneumatic conveyer for granular or pulverulent material, the combination of a conveying duct, means for creating a movement of air therethrou h,and mech-.

anism .for feeding material into said duct comprising a casing arranged above said duct, having a feed passageway, a feed chute, a valve-between said chute and passageway which opens into the latter, a valve between said assageway and duct which opens into'the not, a diaphragm, and means for vibrating the same so as to open and close said valves in alternation.

17 In a pneumatic conveyer for granular or pulverulent material, the combination of aconveying duct, means for creating a movement of air therethrough, and mechanism for feeding material intoflsaid duct duct, having a steed passageway, a feed chute, a flexible fl'ap valvebetween said chute and passageway which opens into the latter, a flexible'fl'ap valve between said passageway and duct which opens into the duct,

a diaphragm, and means for vibratingthe :ame soas to open said valves in alterna-- ion.

18. In a pneumaticconveyeixfor granular or pulverulent material, thecoinbination of a conveying duct, means for creating a movement of air therethrough, and mechanism for feeding material into-said duct comprising a casing arranged above said duct, having a feed pa'ssagewayaa feedchute opening into the top of the casing,.said caslug being formed with a receiving surface below said chute, a valve between said chute and passageway opening into the latter, a,

valve between the passageway and duct opening into the duct, a flexible diaphragm arranged in the side wall ofthe casing, and means for-vibrating said diaphragm.

" 19. In feeding mechanism for granular or pulverulent material, the combination of a casing having an inlet and outlet, a feed I I passageway which opens into, the latter, a valve between the passageway and outlet which opens toward the outlet, and means for alternately] rarefying and compressing the air in said passageway.

20. In feeding machinsm for granular or.

pulverulent material, the combination of a .passageway, avalve between saidlinlet and.-

casing having an inlet and outlet, a feed passageway, a valve between said inlet and passageway which opens into the latter, a

valve between the passageway and outlet which opens toward the outlet, a diaphragm in the side wall of the casing, and means valves open toward said outlet, a pair of flexible diaphragmsin the side walls of said casing, and means for vibrating said diaphragms together first in one direction and then in the other. I

22. In a pneumatic conveyer for'granular or pulverulent material, the combination of a conveylng duct, an air compressor, a pipe the cross sectional area of WhlCh is not substantially less than the cross sectional area I of said duct extending between said compressor and said duct, means for introducing the material into said duct, anda rotary. impact impeller-located in sa1d duct to act upon the material and forward the same inthe direction of the air current.

23. In a pneumatic conveyer for granular or pulverulent materiahthe combination of a conveying duct, an ai'r compressor, a pipe,

the cross-sectional area'of which is not substantially less than the cross-sectional area of said duct, extending between said comressor and said duct, means for introducmg the material in measured quantities into said duct at regularly timed intervals, and a fotary impact impeller located in .said' duct to act upon the material and forward I the same in the direction of the air current. 1 24. In a pneumatic conveyer for granular or pulverulent material, the combination of a duct for conveying material in a substantially hOI'lZOIltfil dlIfCtlOIl, means for forcing air under pressure into said duct to create a current of air therethrough, means for intermittently feeding measured quantities of material downwardly into this air .current, and animpeller positioned in the duct belowthe feeding means and acting on.

the material suspended in the air current to forward the same in the direction of the air current.

25. In a pneumatic conveyer for granular or pulverulent material, the combination of a duct for conveying materialin a substantially horizontal direction, means for forcing air under pressure into said duct to create a current of air therethrough, means for intermittently feeding measured qu'anti- 10 ties of material downwardly into this air current, and a rotary impeller having blades positioned in the duct below the feedin means and actingon the material suspende in the air current to forward same in the 15 direction of the air current.

- JOE CRITES. J FRED I. RAYMOND. 

